Minimally invasive medical techniques are intended to reduce the amount of tissue that is damaged during medical procedures, thereby reducing patient recovery time, discomfort, and harmful side effects. Such minimally invasive techniques may be performed through natural orifices in a patient anatomy or through one or more surgical incisions. Clinicians may insert medical tools through these natural orifices or incisions to reach a target tissue location. Such endoscopic tools include instruments such as therapeutic instruments, diagnostic instruments, and surgical instruments. To reach the target tissue location, a minimally invasive medical tool may navigate natural or surgically created passageways in anatomical systems such as the lungs, the colon, the intestines, the kidneys, the heart, the circulatory system, or the like.
Endoscopic instruments are typically intended to be used for multiple procedures, and so must be cleaned and sterilized between such procedures. A common sterilization method is the use of autoclaving to apply elevated temperatures and pressures to used instruments to destroy or inactivate bacteria, viruses, and other contaminants that might be found on such instruments. However, some endoscopic instruments can have difficulty surviving such high-temperature environments due to the differing coefficients of thermal expansion of the various components making up such instruments
Instruments that include dedicated cooling structures can be particularly susceptible to such thermal mismatch issues, as the cooling structures are specifically designed or selected to have specific thermal properties that differ from that of the surrounding instrument structure. For example, endoscopes having distal digital imaging sensors can incorporate heat pipes or other thermal conduits to ensure that the heat generated by such imaging sensors are shunted away to prevent damage to the sensors and/or injury to the patient. However, although rigidly fixing the heat pipe to the imaging sensor and some remote heat sink in the endoscope can provide the desired intraoperative image sensor cooling, the post-operative autoclaving of an endoscope with such a construction can be problematic because the heat pipe and the surrounding endoscope structure will exhibit different dimensional changes in response to the elevated thermal load, which in turn can lead to physical failure of the heat pipe and/or its thermal connections.
Accordingly, it is desirable to provide an endoscopic instrument that incorporates thermal management structures capable of surviving large temperature changes in the instrument.